# Test 4: Out-of-Sample Validation

Surface estimated on pre-2010 data; predictions tested against post-2010 actuals.

| DV | Subsample | Predicted Z₁ | Actual Z₁ | Match? | N |
|---|---|---|---|---|---|
| ca_gdp | Full | 41.7 | 11.247 | YES | 2837 |
| ca_gdp | High income | 115.6 | 92.725*** | YES | 904 |
| ca_gdp | Low income | -37.8 | -97.605 | YES | 941 |
| ca_gdp | OECD | -22.5 | -43.564 | YES | 570 |
| gross_savings_gdp | Full | 122.0 | 127.811*** | YES | 2469 |
| gross_savings_gdp | High income | 104.3 | 116.874*** | YES | 860 |
| gross_savings_gdp | Low income | 150.8 | 101.489 | YES | 813 |
| gross_savings_gdp | OECD | 10.5 | 2.035 | NO | 570 |

*7/8 predictions match (same sign, within 4x magnitude).*
